Method for treating ferrous-metal articles



warren STATES Parana oration.

FRANK 1.. sonnn'snn, or DETROIT, meme-AN, Assrenon To THE ranTanraoTncTron' LanoaATonrns, or nnTnorT, MICHIGAN, a conroaa'rron' orinrcnrean.

ranTnon ron TREATING rnnaons-rmran ARTICLES. I

asagna.

Ho Drawing.

To all whom it concern:

Be it known that I, FRANK L. SoRENsEN,

a citizen of the United States, residin at Detroit, in the countyof Wayne and tate of Michigan, have invented a certain new and useful Improvement in Methods for Treating Ferrous-Metal Articles, of which the following is a full, clear, and exact de-' scription.

This invention relates to the treatment of ferrous metal to prevent oxidation and has for its object the provision of aprocess.

which shall be simple and easy of performance whichshall employ only simple and iron or steel surface, a zinc containing cor' rosion-resisting coating is formed. According to the best form of my invention that I have so far discovered I take of sodium hydroxid one part; zinc. oxid ten parts; and comminuted metallic zinc ten parts more or less. I first dissolve the sodium hydroxid in a little water, then 1ncorporate the zinc oxid to form a smooth paste, and finally add the finely dlvided metallic zinc with constant stirring, adding water,if necessary, from time to time,

so as to produce a kind of paste The stiffness of the paste may vary through wide limits, wherefore much latitude is possible in the amount of water employed.

. ihe surface of the metal to be treated is cleaned in any convenient manner, as by said blasting, scrubbing, grinding or acid pickling. If the acidmethod is used, I prefer to neutralize the acid to a considerable extent beforeapplying the coating but mere washing with water is enerally sufiicient,

. inasmuch as a small residue of acid is not detrimental. The pasty mixture is then applied to the surfaceof the metal in any suitable manner, as by a brush, rubbing on with a cloth, or even by spraylng. As

soon as it is applied it is then brushed or rubbed thoroughly onto the surface. This Specification of Letters Patent.

Patented June '7, 11921.

Application filed July 17, 1919. Serial No. 311,575.

friction appears to be very important since ts efl'e'ct is to accentuate the action and improve the coating. The superfluous paste may then be removed either by rinsing or spraying with water either with or without brushing, when it will be found that the article has received a smooth, adherent coating which consists largely of metallic z1nc and which adheres with great tenacity to the ferrous metal article and exhibits great resistance to oxidizing or corroding influences. Paint, varnish and enamel adhere well to this coatingwithout the neces- 4 sity of employing any filling or foundation coating although a filler affords a better coating when paint is used.

The proportions of the ingredients may vary widely and Valuable results be achieved, but the resistance to'the salt spray and other corrosive conditions appears to be at a maximum when the proportion of caustic forms about ten per cent. of the dry mixture, although good results are obtained when the proportion varies between, five and fifty per cent. I have found that other zinc compoundssuch asthe carbonate, or

hydroxid can be substituted for zinc oxid.

and a beneficial coating obtained which is 'suficient for many purposes'although I do not consider the result as good as that obtained with zinc oxid. The degree of comminution may vary widely, though I prefer a rather coarse powder rather than a fine dust, inasmuch as the former gives a greater friction, but either canbe used.

Certain other metals than zinc can be: used, for example, finely divided tin, lead or antimony, inconnection with their oxids, and a base of caustic soda as before, and in each-case there is a similar but thinner coatin'g obtained of the metal used having some protective value, but, of course, not possessin'g the peculiar protective quality which zinc exhibits in connection with ferrous metal. I have also used finely dividedti'rr,"10o" lead, and antimony with caustic soda base but without their oxide and in each case I have obtained a very thin metallic coating with a surface appearance characteristicof the metal used. Wherefore, I claim all these mixtures and coatings and include all.

these ingredients within my general idea of process but prefer for protective purposes on ferrous metal to employ the zinc. mixhim. It willbe noted that all the above 11 0 a inseam metals exhibit the property of producing a soluble compound in conjunction with the alkali used, and also of combining with the metallic compound in the presence of alkali to produce an insoluble basic compound,

The alkali, metallic oxid, and w'atercan be mixed up in advance and he t indefinitely so long as the finely divi ed metal is not added, but the latter should be in corporated with the mixture immediately before using, since the whole will otherwise upon exposure set into a hard mass.

It will he understood that I do not con fine myself to this method of mixing since the order of adding the ingredients is unimportant excepting from a standpoint of convenience, and that other changes can he made within the scope of my invention.

Having thus described my inventiomvvhat T claim is 1 1. The method of providing ferrous metal,

articles with a corrosion resisting coating which consists in the frictional application to the surfaces of the same, of a mlxture of caustic alkali and water .together with a second metal in finely divided form and an oxygen compond of said second metal, said second metal being of a nature which will combine with caustic alkali to produce a soluble compound 2. The method of providing ferrous metal articles with a corrosion resisting coating which consists ,in the frictional application to the surfaces of such articles, of a mixture of caustic alkali and water together with a compound of a second metal and a finely comminutedmetal of such nature as to tend to combinewith such compound in the pres ence of alkali with the production of an insoluble compound.

3. The method of providing ferrous metal articles with corrosion resisting coating which consists in applying thereto a mixture containing caustic alkali, water, a second metal adapted to combine with such caustic alkali and an insoluble compound of some metal which is adapted to combine with caustic, alkali to produce a soluble compound; second, forcing such mixture into close contact with all parts of the ferrous surface; and, third, rinsing. away the excessive mixture. I

d. The method of providing ferrous metal articles with a corrosion resisting coating which contains the step "that of the alkali.

of applying thereto frictionally a mixture of an insoluble com-.

6. The method of providing ferrous metal articles with, a corrosion resisting coatingwhich consists in the to the surface thereof of a zinc compound mixed with caustic alkali, water and finely divided zinc, the amount of the zinc compound and of metallic zinc heing each from about two to about twelve times as great as frictional application 7. The method of providing ferrous metal with a corrosion resisting coating which consists in the frictional application to the roughened surface thereof another metal in finely divided form to.-

gether with the oxid of said other metal and caustic alkali and water, said second metal losing of a nature to combine with the oxid in the presence of alkali and water with the production of an insoluble hasic compound.

8. The method of providing ferrous metal with a corrosion resisting coating which consists in the frictional application to the roughened surface thereof of a mixture of another metal in finely divided form together with a non-ferrous, metallic commetal adapted to corn of a mixture of pound, caustic alkali and water, said other metal being of a nature to combine with said metallic compound in the resence of alkali and water with the pro notion of an in soluble compound. I

9. The method of providing metal with a corrosion resisting coating which consists in the frictional application thereto of a mixture of another metal in finely divided form together with a compound of said other metal and caustic alkali and water.

10. The method metal articles coating which thereto with oxygen compound, finely divided metallic zinc.

In testimony. whereof, ll hereunto afiix my signature.

FRANK L. O RENST3N;

with a corrosion resisting contains the step of applying friction a mixture of a zinc of providing ferrous caustic alkali, water and 

